MIsfire on Cylinders 2, 4, 6 after replacing injectors 1, 3, 5 adn fuel filter

I have a 2000 Tacoma Pre-runner 5VZ V6. It initially was missing on cylinder #5 and it tested bad so I replaced the injectors on the right side, 1,3, 5, because why not. While the fuel system was depressurized, I also replaced the fuel filter ( LONG time coming). I did NOT touch the driver side injectors at all, they were replaced back in 2018 or so.

I also cleaned the throttle body and the IAC while I had it off. Now, the car starts up fine, and you cannot feel a miss, though once it warms up, the idle will drift a bit down to 550RPM's and be a little rough, but then jump up to about 700, in gear, and run smooth. NOrmal driving feels normal and it has plenty of power with 275k on it. But it throws codes P0300, P0302, P0304 and P0306.

I feel like I am missing something, clearly, but cannot figure out out. Anyone ever heard of this before?

 

Are you sure the codes aren't P0302, 0304, and 0306?

200, 400, and 600 aren't "normal" codes.

 

Yes, sorry, 302, 304, 306 and 300.

I fixed my original post.

 

Dual electrode plugs in all cylinders?

 

The CKP detects the misfire.
Were the injectors the same as the others you put in.

A change in crankshaft speed difference between cylinders can throw a misfire code.

Just brainstorming here.

 

Plugs and wires were replaced a few years ago, as well as coils. Dual electrode denso plugs as required.

Truck ran fine, except for #5 injector testing bad prior to this.

I feel like there may be air in the fuel line since the misses are all on the driver side, though again, you can’t really feel any missing, though it does have a low idle that is a little bumpy sometimes. But feels normal

 

All those codes are misfires….
Appears that they are they all on opposite side of the side you worked on

Sorry, I don’t know firing order of your V6 to confirm
But
The new injectors performing perfectly might just be causing misfiring on the opo side with the 175k mile injectors
(Old injectors can’t keep up with the new ones)
Interesting
Lets us know

 

Yes I know they are all misfires. They are all happening on the same side. Driver side. It’s a V6 so cylinders 2, 4 and 6 are in the driver side. They were fine until replacing passenger side injectors.

it’s very strange. I was hoping someone may have had this happen or heard of this sort of thing happen. Not sure what else to do, especially since it seems to run fine.

 

If the computer is tuning to the new injectors or the new average, the old ones may be driven incorrectly. I don’t know how the algorithm works, but it is suspicious that the old side is misfiring.
Any experts out there?

 

Do you have the plug wires and injector wires connected correctly?

What do your fuel trims look like?

Where did the injectors come from?

 

There should be very little to no difference in injector flow rates, if there is then you have a problem.

 

You could swap #1 injector with #2 & see if the code follows.

 

I find it curious that the misfires are all with the plugs that are all connected via the plug wire and not the cylinders where the coil bolts directly on. Are the wires routed properly and separated via the hold downs? There is a possibility that the could be a crossfire situation with the plug wires if not separated, the insulator shielding isnt that thick. This type of ignition system is what the industry calls a wasted spark system. When the coil for what ever cylinder is commanded to fire to ignite the fuel the spark plug for the companion cylinder that is not on TDC compression fires also. As mentioned above, the crankshaft position sensor (CKP) is sensitive enough to recognize the slowdown of the crankshaft during a misfire and recognizes it. Were Toyota wires and coils used when you replaced them?

 

OK I will add that the plugs or wires were NOT disconnected when we did the job, so no crossed wires or anything of that fashion. I removed the throttle body and was able to remove the rail to replace the injectors on the the passenger side. I also cleaned the throttle body and IAC while I had it off and replaced the fuel filter, but did not touch the driver side in any way.

The injectors are JDMON on Amazon. Price was a big factor at this time.

I know there is a learning time for the PCM after cleaning the throttle body, but just really odd that all the misfires are only on the side I did not touch at all.

 

I'd be highly suspect of Amazon injectors, your better off replacing the one bad one with an OEM one than replacing all 3 with some of questionable quality.

I think I'd put the old ones back in and see if you go back to the original problem, if you do then replace the bad one with an OEM one.

 

@The Gare Do you have a “brain-tickler” that reads fuel trimmings?

 

Thing is I am not getting misfires on the Amazon injectors. And I would not normally buy anything but OEM, but money is tight. The original #5 injector did test bad, as I suspected when this all started.

 

I do not. I have a friend that does have more specialized tools though I am gonna hit him up.

I drove it today, CEL is on, not flashing, and it runs fine, no miss that can be felt at all. Idle is bumpy, then seems to reset itself, but no noticeable miss whatsoever.

 

That's why i asked if they were the same brand and type as the ones he installed a few years ago on the other bank.
My under standing is that the CKP sensor detect a misfire by detection changes in crankshaft speed.
I the new injectors are injecting a different amount or a delayed injection than the ones on the other bank, maybe that's why the entire bank is reading a misfire?

Or is that even possible?

I don't?
But to change one bank, and then have the other bank you didn't touch throw misfires, is odd?

 

Do you still have the other original injectors you replaced to make a full set of OEM Injectors?

I'm not sure where you are in the country, but there are places that clean and service injectors. Motorwest Performance is the most suggested.

If you don't have all the OEM injectors, I actually have a spare set that I would be willing to pass on at this point for a reasonable price.